Update: see post 8 for a solution.


This post is aimed at hardware, EE gurus- that possibly have tried this already.

I have read everything I can find on the topic, and even built my own Y-cable to charge N900 from self-powered premium USB Hub that offers 500mA per port.

Sadly even under this scenario N900 still charges only at the 100mA - even though 1A is consistently available.

I looked at charger specification of N900 and I understand that i2cset command should be able to set the charging basen on Iin_limit
registers.

I know that this register value can be set to 500mA, or 800mA for charging and needs to be refreshed every 30 seconds or so - run from within the loop just like what is done to make USB host mode work.

I have purchased spare batteries, but it really makes no sense that n900 that is always hooked-up as a 3G modem to a Tomato firmware based router - dies due to lack of power after just after few hours of use.

This happens when the USB delivers 500mA per port and even with Y-Cable (power insertion) - yet N900 claims "not charging insufficient power" if the LCD is lit.

The bottom line is that I would like someone to verify what the actual command for i2cset command line should be to set it to 800mA - because I am not an expert and do not want to cause any issues for myself by accident.

Even the i2cset command that sets it to 100mA would be sufficient for me to figure out how to change it to 500/800 modes.

N900 is just not smart enough to detect the actual charging situation and the USB Host and shutting the BME, still seems to only use 100mA - if there is no actual host to interrogate and agree on what the vbus usb spec for charging is.

Even with solid yellow/orange light on(so called fast charge mode) - I believe my N900 slow charges with 100mA by default.

Please help informed users to set the charging speed manualy.
Even if the sample command would be referring to existing insufficient defaults.

This is the only peeve I have with my n900 - all other issues I have managed to solve by now.

Thanks in advance!

netC